Fix Netkan error message when both ksp_version and ksp_version_min/_max are present

[HebaruSan]

Problem

KSP-CKAN/NetKAN#6654 got tripped up by this very confusing error message:

9493 [1] FATAL CKAN.NetKAN.Program (null) - Exception has been thrown by the target of an invocation.

The root cause was that the generated metadata had this:

  "ksp_version": "1.4.0",
  "ksp_version_min": "1.4.0",
  "ksp_version_max": "1.4.99",

These properties aren't supposed to be combined; either you have ksp_version, or you have _min and/or _max. We have a check for that with its own special exception here:

CKAN/Core/Types/CkanModule.cs

Lines 444 to 449 in 4120e9b

	// Now see if we've got version with version min/max.
	if (ksp_version != null && (ksp_version_max != null || ksp_version_min != null))
	{
	// KSP version mixed with min/max.
	throw new InvalidModuleAttributesException("ksp_version mixed with ksp_version_(min|max)", this);
	}

However, that info wasn't making it all the way to the output.

Changes

Netkan now uses Exception.GetBaseException() to strip away useless wrapper exceptions.

InvalidModuleAttributesException now passes its why parameter to its base class's constructor, which populates Exception.Message for Netkan to print out.

Now the error looks like this instead:

1344 [1] FATAL CKAN.NetKAN.Program (null) - ksp_version mixed with ksp_version_(min|max)

[politas]

Cool! That confusing error message has lead to much scratching of heads!

[linuxgurugamer]

This comment:

The root cause was that the generated metadata had this:

"ksp_version": "1.4.0",
"ksp_version_min": "1.4.0",
"ksp_version_max": "1.4.99",
These properties aren't supposed to be combined; either you have ksp_version, or you have _min and/or _max. We have a check for that with its own special exception here:

is wrong. While duplicative, it is fine to have both. If min/max are there, the ksp_version is ignored.

[HebaruSan]

That comment is correct. CKAN throws an exception in that case:

CKAN/Core/Types/CkanModule.cs

Lines 444 to 449 in 4120e9b

	// Now see if we've got version with version min/max.
	if (ksp_version != null && (ksp_version_max != null || ksp_version_min != null))
	{
	// KSP version mixed with min/max.
	throw new InvalidModuleAttributesException("ksp_version mixed with ksp_version_(min|max)", this);
	}

[HebaruSan]

I think you're thinking of how KSP-AVC treats .version files, which is not the same as how CKAN treats its module metadata.

[linuxgurugamer]

oops, you are correct